Electrical circuit card connector

Abstract

A connector for interfacing a circuit resident on a printed circuit board having rows of externally accessible contact pads on a face of the board with a circuit resident on a portable card having rows of externally accessible contact pads on a face of the card has independently biased ball bearing contacts which assure positive, self-cleaning, self-sealing, self-adjusting electrical contact between the circuits. A flat base has rows of apertures therethrough spaced for alignment with the pads of the board when the base is laminarly juxtaposed on the face of the board. Sinks connect the apertures in rows and the conductive ball bearings are retained in each of the apertures by annular shoulders on the apertures. Strips of elastomer formed of layers of conductive and dielectric materials are snugly seated in each sink with the layers transverse to the rows. The strips bias the ball bearings against the shoulders when the base is laminarly juxtaposed on the face of the board. Feet and bosses on the connector engage with sockets and dimples on the board to rigidly connect the base to the board with the strips in abutment with the rows of pads on the board. A housing fixed to the base receives, aligns and holds the card in laminar juxtaposition against the ball bearings so that discrete conductive paths are defined by aligned card pads, ball bearings, elastomer layers and board pads.

What is claimed is: 
     
       1. A connector for interfacing a first circuit resident on a printed circuit board and having rows of externally accessible contact pads on a face of the board with a second circuit resident on a portable card and having rows of externally accessible contact pads on a face of the card, the connector comprising: a flat base portion having rows of apertures therethrough spaced for alignment with the pads of the board;   a plurality of conductive ball bearings, one disposed in each of said apertures;   shoulder means annularly disposed along one edge of each of said apertures for retaining said ball bearings therein;   resilient means extending from another edge of each of said apertures to said ball bearings for independently biasing said ball bearings against said retaining means and having a conductive portion for providing a discrete conductive path between aligned board pads and said ball bearings when said base portion is laminarly juxtaposed on the face of the board;   mounting means fixed to said base portion for rigidly connecting said base portion to the board with said resilient means in conductive contact with aligned pads on the board; and   guide means fixed to said base portion for aligning and holding the card in laminar juxtaposition against said ball bearings whereby discrete conductive paths are defined by aligned card pads, ball bearings, resilient means and board pads.   
     
     
       2. A connector for interfacing a first circuit resident on a printed circuit board and having rows of externally accessible contact pads on a face of the board with a second circuit resident on a portable card and having rows of externally accessible contact pads on a face of the card, the connector comprising: a flat base portion having first and second faces and rows of apertures therethrough spaced for alignment with the pads of the board when said first face is laminarly juxtaposed on the face of the board, each of said apertures having an annular shoulder at said second face, and a plurality of sinks in said first face connecting said apertures in rows;   a plurality of conductive ball bearings, one retained in each of said apertures by said shoulders;   a plurality of strips of elastomer having conductive and dielectric layers, one snugly seated in each said sink with said layers transverse to said rows, said strips biasing said ball bearings against said shoulders when said first face is laminarly juxtaposed on the face of the board;   first means fixed to said base portion for rigidly connecting said base portion to the board with said strips in abutment with the rows of pads on the board; and   second means fixed to said base portion for receiving, aligning and holding the card in laminar juxtaposition against said second face with said ball bearings in contact with the pads of the card whereby discrete conductive paths are defined by aligned card pads, ball bearings, elastomer layers and board pads.   
     
     
       3. The connector according to claim 2, said annular shoulders comprising a lip integral to said base portion and inwardly tapered to said second face. 
     
     
       4. The connector according to claim 2 further comprising a plurality of ribs integrally inwardly projecting into each of said sinks for gripping said strips of elastomer therebetween. 
     
     
       5. The connector according to claim 2, said strips having a depth greater than the depth from said first face to said ball bearings seated against said shoulders whereby said strips are compressed between said ball bearings and the board when said first face is in abutment with the board. 
     
     
       6. The connector according to claim 5, said sinks having bevelled edges along said first face into which said strips partially expand when said strips are compressed between said ball bearings and the board. 
     
     
       7. The connector according to claim 2, said second means having a bevelled mouth for slidably receiving the card therein. 
     
     
       8. The connector according to claim 2, said second means having a portion protruding toward said ball bearings for holding the card in firm slidable engagement with said ball bearings. 
     
     
       9. The connector according to claim 2, the board having sockets therethrough and said first means comprising feet depending from said first face and insertable into and slidable with said connector in relation to said sockets. 
     
     
       10. The connector according to claim 9, the board having dimples therein and said first face further comprising complimentary bosses thereon engaging with said dimples when the pads on the board are aligned with said ball bearings. 
     
     
       11. A connector for interfacing a first circuit resident on a printed circuit board and having rows of externally accessible contact pads on a face of the board with a second circuit resident on a portable card and having rows of externally accessible contact pads on a face of the card, the connector comprising: a base member having rows of apertures therethrough spaced for alignment with the pads of the board, each of said apertures having an annular shoulder at one end thereof, and a plurality of sinks connecting said apertures in rows;   a plurality of conductive ball bearings, one retained in each of said apertures by said shoulders;   a plurality of strips of elastomer having conductive and dielectric layers, one snugly seated in each said sink with said layers transverse to said rows;   first means fixed to said member for rigidly connecting said member to the board with said strips in abutment with the rows of pads on the board; and   second means fixed to said base for receiving the card in laminar juxtaposition against said second face with said ball bearings in contact with the pads of the card whereby discrete conductive paths are defined by aligned card pads, ball bearings, elastomer layers and board pads.   
     
     
       12. A connector for interfacing a first circuit resident on a printed circuit board and having rows of externally accessible contact pads on a face of the board with a second circuit resident on a portable card and having rows of externally accessible contact pads on a face of the card, the connector comprising: a housing having a flat base, a flat cover and a flat, narrow, externally accessible passage therebetween for laminar insertion of the card therein, said base having first and second faces and rows of apertures therethrough spaced for alignment with the pads of the board when said first face is laminarly juxtaposed on the face of the board, each of said apertures having an annular shoulder at said second face, and a plurality of sinks in said first face connecting said apertures in rows;   a plurality of conductive ball bearings, one retained in each of said apertures by said shoulders;   a plurality of strips of elastomer having conductive and dielectric layers, one snugly seated in each said sink with said layers transverse to said rows, said strips biasing said ball bearings against said shoulders when said first face is laminarly juxtaposed on the face of the board;   means fixed to said base for rigidly connecting said base to the board with said strips in abutment with the rows of pads on the board; and   side walls connecting said base and said top for aligning the card with said ball bearings in contact with the pads of the card whereby discrete conductive paths are defined by aligned card pads, ball bearings, elastomer layers and board pads.   
     
     
       13. A connector for interfacing a first circuit resident on a printed circuit board and having rows of externally accessible contact pads on a face of the board with a second circuit resident on a portable card and having rows of externally accessible contact pads on a face of the card, the connector comprising: a housing having a flat base and a flat cover spaced by side walls to define a flat, externally accessible passage for receiving, guiding and holding the card in laminar position between said base and said cover, said base having inner and outer faces and rows of apertures therethrough spaced for alignment with the pads of the board when said outer face is laminarly juxtaposed on the face of the board, each of said apertures having a tapered shoulder along an outer end thereof, and a plurality of sinks in said outer face connecting said apertures in rows;   a plurality of conductive ball bearings, one retained in each of said apertures by said shoulders;   a plurality of strips of elastomer having conductive and dielectric layers, one snugly seated in each said sink with said layers transverse to said rows, said strips biasing said ball bearings against said shoulders when said outer face is laminarly juxtaposed on the face of the board; and   means fixed to said base for rigidly connecting said base to the board with said strips in abutment with the rows of pads on the board whereby, when the card is inserted into said passage, discrete conductive paths are defined by aligned card pads, ball bearings, elastomer layers and board pads.   
     
     
       14. The connector according to claim 13 further comprising a plurality of ribs integrally inwardly projecting into each of said sinks for gripping said strips of elastomer therebetween. 
     
     
       15. The connector according to claim 14, said sinks having a depth greater than the depth from said outer face to said ball bearings seated against said shoulders whereby said strips are compressed between said ball bearings and the board when said outer face is in abutment with the board. 
     
     
       16. The connector according to claim 13, said apertures having bevelled edges along said outer face into which said strips partially expand when said strips are compressed between said ball bearings and the board. 
     
     
       17. The connector according to claim 13, said passage having a bevelled mouth for slidably receiving the card therein. 
     
     
       18. The connector according to claim 13, said cover having a land protruding from said inner face thereof toward said ball bearings for holding the card in firm slidable engagement with said ball bearings. 
     
     
       19. The connector according to claim 13, the board having sockets therethrough and said means comprising feet depending from said outer face and insertable into and slidable with said connector in relation to said sockets. 
     
     
       20. The connector according to claim 19, the board having dimples therein and said outer face further comprising complimentary bosses thereon engaging with said dimples when the pads on the board are aligned with said ball bearings.